Β-Agarase

Function in Environment

As could be expected, many species of agar-degraders are marine micro-organisms – an adaptation to their environment which would be wasted in the majority of micro-organisms existing on land (although there are such examples, including a species of Paenibacillus in the Rhizosphere of Spinach). From species within genus Vibrio to Alteromonas, the presence of agarase allows agar-degrading bacteria an abundant food source in the ocean. Research also demonstrates that glucose can inhibit extracellular agarase secretion (but not transcription), causing it to degrade within the cell and thus limit growth of the bacteria. This further highlights the niche which this class of bacteria usually occupies, as the concentration of glucose or phosphate in the ocean is very low while magnesium concentration is generally much higher, suiting the agar-degrading bacteria’s agarase production; there is simply no need to use glucose in the ocean, so many organisms don't.

While the optimal pH of agarase is 5.5, it is stable at a tolerant range, from 4.0 to 9.0.

References

References

1. (1994). "Effect of glucose on agarase overproduction in Streptomyces.". Gene.
2. (2001). "Production and separation of α-agarase from ''Altermonas agarlyticus'' strain GJ1B.". Bioresource Technology.
3. (2003). "Isolation and characterization of agar-degrading ''Paenibacillus'' spp. Associated with the Rhizosphere of Spinach". Bioscience, Biotechnology, and Biochemistry.
4. (1990). "Purification and characterization of a novel β-agarase from ''Vibrio'' sp. AP-2". European Journal of Biochemistry.
5. (1992). "Purification and Properties of an Extracellular Agarase from Alteromonas sp. Strain C-1". Applied and Environmental Microbiology.
6. (1998). "Effects of phosphate limitation on agarase production by ''Streptomyces lividans'' TK21". FEMS Microbiology Letters.